超细晶粒钢低热输入CO2气体保护焊接头行为分析  

Ultra-fine grain steel welded joint behaiour of CO_2 arc welding under low heat input

作　　者：张富巨[1] 王燕[2] 张国栋[1] 王玉涛[3] 

机构地区：[1]武汉大学动力与机械学院,武汉430072 [2]三峡大学机械与材料学院,湖北宜昌443002 [3]武汉钢铁集团公司研究院,武汉430080

出　　处：《焊接学报》2008年第2期77-80,共4页Transactions of The China Welding Institution

摘　　要：研究了400MPa级超细晶粒钢基于表面张力过渡、CO2气体保护焊、特殊窄间隙坡口、不同热输入条件下的焊接接头的成形与力学行为。结果表明,热输入在3～4kJ/cm范围时可获得熔合良好、单面焊双面成形、热影响区极窄(1mm左右)的焊接接头。该接头的硬度、抗拉强度高于母材,未见热影响区脆化与软化现象;弯曲塑性合格;焊接热影响区平均冲击韧性高于母材约60%。焊接热影响区冲击韧性高于母材的原因与粒状珠光体组织生成、多相非平衡组织共存和更高的屈服应力有关。The formation and mechanical properties of welded joint for 400 MPa ultra-fine grain steel were studied based on surface tension transfer technology,CO2 arc welding,special narrow groove and different heat input.The results showed that the welded joint with good fusion,one side welding with back formation and narrow HAZ(heat-affected zone)(about 1 mm)was obtained with 3-4 kJ/cm heat input.The hardness and tensile strength of the joint were higher than those of the base metal.The embrittlement and softening of HAZ was not found,and the bending plasticity was qualified.The impact toughness of HAZ was about 60% higher than that of the base metal,which can be caused by the granular pearlite transition,multi-phase non-equilibrium microstructure and higher yield stress.

关 键 词：超细晶粒钢 焊接接头 焊接热输入 CO2气体保护焊 

分 类 号：TG457.11[金属学及工艺—焊接]